Underwater periscope



June 1954 J. P. KQHUT UNDERWATER PERISCOPE Filed June 21 1951 INVENTOR.JOfEPH P. KOHUT BY 2 5 Z A 7" TORNE) Patented June 8, 1954 NI ED 'STATES.PATENT OF EE UNDERWATER ER SQQPE J se h 59, 3 New BFF B WJQ S Apication an. 21, 1951; see Ne. 232.765

This invention relatesto periscopes in general, and provides,in'part'icular; a'pprtab1e and adjustable device for viewing 'obJeotswhi'oh are under Water from a point above the surface of the water.

The invention part ular utility in the observation and coaehiii ofswimmers during training, andin'olosejrvingvarioussorts of underwateraction, either from the side of a swimming pool or'other stable support.QThedeVice may also be used on boats/a id it is easily portable."

One of the problems in coaching swimmers in proper form and in observingsub surface action during life-savingte'sts' and the likeQis to securecomplete visibility of the sub-surface action taking place. This cannotbe had from Viewing the action from above the surface of the water;since waves and the difference in refractive index be tween air andwater distort the observed objects. Some special pool installations havebeen made with sub-surface observation] windows. While these aregood,they are'lik'ewise expensiva'and have a disadvantage of distortingperspective when the line of sight departssubs'tantially from a normalto the plane of the observation window.

The device of this invention findspai'tioular utility in pools,whe'rano'"sub-surface observa tion facilities are permanentlyinstalled. liurthermore, it may be constructed of (seve e n and readilyavailablamaterials, and is within reach, 'costwise, of the" majority ofindividuals and-organizations'who have need ior an under waterobservation instrument."

An object of the invention'is to provide a simple inexpensive underwaterobservation instrui n ent having great flexibility. T 't her objectswill become apparentas a'detailed'de'soription proceeds. In thedrawings, in which similar reference characters designate similarpart s,

Fig. 1 is a section through the instrument, and Fig. 2 is a front viewof the instrument as it might be seen from the water.

' My underwater observation instrument O .119- vice comprises a more orless pyramidal shaped four-sided sheet metalfhousing member ilifat.

the lower end of which are inbent shelves 12 to support a glass plateL4. The plate is held in position by sealing compound or ga s kets toavoid water entry within the housing, and is retained by angle bracketsl -6 suitablysecured tothehous in The plane o h g a L i su s ant allynormal to the line [B which may be consideredas the Optical ax o thenstrumen Thi axis is tilted relative t the verticahand likewise, theglass 4 i li h y ti ted from the. horizontal.

'When the lower end .ofthe instrument is sub- 4 Claims. (o1. s r-es)merged, any bubbles entrained on the glass will 11am he iipr eii the gass e 5 n e the is'Ynorrrial' to the glass; the under surraceorthe'g'lass Mbeing wholly 'wetted by im mersion, there will besubstantially no distortion in refracted. 'i'm "'swhich otherwise mightoccur due to are substantial diiierence' in the index of redeeme between'air and ater.

"re the lowermost je l' 'zg er the housing ID, a hinge '22 is securedupon which aplate 24 is mounted. l' Ihifspla'te carries a mirror 26,secured by clips or by enting and the mirror will normally besetat anangleof about {15 to the vertidal. However, to'enabl'e observation of under water phenomena over a wide range of depths,

the mirror as may be tiltedon'the hi g 22 from ang es, or aldoutf' icito A quadrant as is secured to the plate 2 4 and a slot 30' therein maybe' engaged by thujmb. screw 32 carried by a smalle bracket secured toone of theside plates of'tl e housing." If no variation in depthofobservation is desired; the mirror plate :24 may be fixedly securedtothe'housin'g H) by gusset plates in'place' of the adjustable ouadrant.

The mirror 2,6 is.preferably trapezoidal in iorm with'tlie, shorter ofits two parallel sides adjacent he hinge 22 and the longer ofits twoparallel s es depending beneath the water. By virtue Z this mirrorshape, the image projected from the mirror up through-the housing IDwill av a na a arm- 1 A the u pe and 9 he h us n ii a se on m r 3 1 i scure (t is 1. 39? fi i y l i g at an angle of from 10. to to the planeof the p1 idee he ins m n as ind cate by he" ey image in Fig. 1. Theupper mirror .35 serves to nrreq t ie nverted im -refl cte b th m r 9tha th cha re ob ects appea in the i e ii in n rma p i h pgs ti i i- A rber x m i 5 ma be p videdaround th u per nd o housi 9 o ye n ace ot iAlso .thc npe ndqfthe hou n i onrmed a shown a Al to nd cate th r perdirection t qm w ch the m ror fifieshould, b .Qb- Served to encomp theentire field o v w afforded by the mirror system. A- small light aflifiz is pr vided a ong the rear wall of the housing In so that the properposition for observation may be established .to enable an obe H 9 ht-ima e efie idf om th mi ror e eaned f om a pain abQi an t he r 3image. The inside of the instrument is preferably painted a dull blackto avoid reflections from the walls. The lower submerged mirror isconsiderably larger thanthe upper mirror to yield a wide field of viewwithout the use of a lens system which would make the instrument deli-'cate and more costly. A practical small-sized instrument of thistypeutilizes a lower submerged mirror approximately 9 by 18 inches, a glassplate M of approximately 6 by inches, and an upper mirror about 4 by 5inches, the height of the entire instrument being about three andone-half feet.

The rear portion of the housing I0 is provided with metal fittings 44and 45 adapted to be pivotally attached to a bracket structure 45 bymeans of pivot screws or pins 47 and '48. The bracket is constructedwith a hooked upper end 58 and a depending strut 52 so that the entireinstrument assembly may be hooked over the gutter of the conventionalswimming pool. Wing screws 54 are provided in the leg 52 to adjust thebracket element snugly on the pool edge so that it is free fromwobbling.

In use the instrument is hung on the edge of the pool as above indicatedand an observer may stand on the pool edge observing underwater actionthrough the instrument. The instrument may be rotated about the pivots41, 48 so that the entire length of the pool may be scanned. Thereby, athorough view of underwater objects is secured. In particular, incoaching swimming, a student swimmer may swim back and forth along theusual yard pool and a coach may observe his every action since his bodyis predominantly below the surface. Thus the coach is able to observedefects in form and to apprise the students of these defects to increasetheir proficiency. Also, accurate observation of under water action maybe had during tests for lifesaving qualifications and the like to assureobservers and coaches that a candidate for lifesaving award isperforming all of his test feats with skill and propriety.

An additional feature of the disclosed device includes buoyancy. Thewholly submerged lower mirror, along with the housing, has suificientweight to partially submerge the instrument, and it is left free in thewater, it will float in a stable upright position with the upper endpro- F truding from the water. This arragement assists an observer ininstalling the instrument on a supporting structure, and preventscomplete immersion'a'nd sinking of the instrument. Clearly, the wholehousing structure is madewatertight and the instrument may be builtquite ruggedly to withstand normal handling by unskilled people,

while yielding effective results.

Though but a single embodiment illustrating the invention has beenillustrated and described, it is to be understood that the invention maybe applied in various forms. Changes may be made in the arrangementsshown without departing from the spirit or scope of the invention aswill be apparent to those skilled in the art and reference should bemade to the appended claims for a definition of the limits of theinvention.

What is claimed is:

1. A viewing device for visually scanning objects beneath the surface ofwater from a point thereabove comprising a substantially vertical hollowmember, a sloped mirror near the upper end of the member, asubstantially horizontal but slightly tilted glass plate water-tightlysealed at the lower end of the member, said plate being 4 Vsubstantially normal to a line of sight from the mirror center throughthe plate center and said plate being tilted to enable dispersion ofbubbles collected thereon upon immersion of the device to the uppermostpart of the plate, a sloped normally wholly submerged mirror oftrapezoidal shape with its shorter base secured to the member adjacentone edge of said plate and lying beneath and outside or" said hollowmember, said submerged mirror having its reflecting surface uppermostand positioned to reflect images of objects beneath the water surfacesubstantially vertically through said plate to said upper mirror.

2. A viewing device for visually scanning objects beneath the surface ofwater from a point thereabove comprising a substantially vertical hollowmember, a sloped mirror near the upper end of the member, asubstantially horizontal but slightly tilted glass plate water-tightlysealed at the lower end of the member, said plate being substantiallynormal to a line of sight from the mirror center through the platecenter and said plate being tilted to enable dispersion of bubblescollected thereon upon immersion of the device to the uppermost part ofthe plate, a sloped normally wholly submerged mirror of trapezoidalshape with its shorter base secured to the member adjacent one edge ofsaid plate and lying beneath and outside of said hollow member, saidsubmerged mirror having its reflecting surface uppermost and positionedto reflect images of objects beneath the water surface substantiallyvertically through said plate to said upper mirror, and bracket meanssecurable to a stationary object such as the side of a. swimming poolupon which said hollow member is pivoted on a substantially verticalaxis to enable the device to be traversed laterally, a line normal tosaid glass plate being slightly acutely angled relative to said verticalaxis of the bracket to assure tilting of said plate and dispersion ofbubbles therefrom.

3. A viewing device for observation of underwater objects from above thesurface of water comprising a substantially vertical hollow member whoselower end is adapted to be submerged and whose upper end is adapted tolie above the water surface, a set of sloped mirrors, one within andnear the top of the member and one secured beneath and outside of themember and adapted to be wholly-submerged, a glass plate secured insealed relation to the bottom of the member above said lower mirror andbetween said mirrors so that its lower surface may be wholly wetted,said plate being tilted slightly from the horizontal whereby bubblescollecting thereon during immersion may float to the uppermost plateedge, the plane of said plate being substantially normal to a lineconnecting the centers of said mirrors, and a substantiallyvertical-axis pivot bracket secured to said member for mounting thedevice on a suitable support, a line normal to said glass plate having asmall acute angle to said verticalaxis pivot to assure tilting of saidplate and dispersion of bubbles therefrom.

4. A viewing device for observation of underwater objects from above thesurface of water comprising a substantially vertical hollow member whoselower end is adapted to be submerged and whose upper end is adapted tolie above the water surface, a set of sloped mirrors, one within andnear the top of the member and one secured beneath and outside of themember and adapted to be wholly submerged, a glass plate secured insealed relation to the bottom of the member above said lower mirror andbetween said mirrors so that its lower surface may be wholly wetted,said plate being tilted slightly from the horizontal whereby bubblescollecting thereon during immersion may float to the uppermost plateedge, the plane of said plate being substantially normal to a lineconnecting the centers of said mirrors, and a substantiallyvertical-axis pivot bracket secured to said member for mounting thedevice on a suitable support, said lower mirror being substantiallytrapezoidal in planform with the shorter of its two parallel sidessecured to said member adjacent an edge of said glass plate, a linenormal to said glass plate having a small acute angle to saidvertical-axis pivot to assure tilting of said plate and dispersion ofbubbles therefrom.

References Cited in the file of this patent Number 1,156,782 1,207,4181,480,112 1,521,339 1,578,958 2,252,640 2,516,897

Number UNITED STATES PATENTS Name Date Jenkins Oct. 12, 1915 LazarteDec. 5, 1916 Poppenhusen Jan, 8, 1924 Taylor Dec. 30, 1924 Daoust Mar.30, 1926 Nuchterlein Aug. 12, 1941 McCullough Aug. 1, 1950 FOREIGNPATENTS Country Date Germany Aug. 6, 1907

